Buses need to get bigger and carry more people per driver (i.e. turn into trains)

Fares have to continue to go up faster than the rate of inflation

Public subsidy has to rise, also faster than the rate of inflation

Buses need to get faster – do the same route in less time (while not losing any passengers)

I neglected to mention a fifth possibility (related to the first): automated trains like the ones in SeaTac Airport or Vancouver’s SkyTrain. This is a perfect Baumol-style productivity upgrade for a transit system to keep pace with rising living costs.